+

US4451649A - Process for the production of hydroxypropyl starch - Google Patents

Process for the production of hydroxypropyl starch Download PDF

Info

Publication number
US4451649A
US4451649A US06/428,853 US42885382A US4451649A US 4451649 A US4451649 A US 4451649A US 42885382 A US42885382 A US 42885382A US 4451649 A US4451649 A US 4451649A
Authority
US
United States
Prior art keywords
starch
propylene oxide
hydroxypropyl starch
production
water
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Fee Related
Application number
US06/428,853
Inventor
Helwig Teubner
Wilhelm Oppermann
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Dow Produktions und Vertriebs GmbH and Co oHG
Original Assignee
Wolff Walsrode AG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Wolff Walsrode AG filed Critical Wolff Walsrode AG
Assigned to WOLFF WALSRODE, AKTIENGESELLSCHAFT,A CORP. OF GERMANY reassignment WOLFF WALSRODE, AKTIENGESELLSCHAFT,A CORP. OF GERMANY ASSIGNMENT OF ASSIGNORS INTEREST. Assignors: OPPERMANN, WILHELM, TEUBNER, HELWIG
Application granted granted Critical
Publication of US4451649A publication Critical patent/US4451649A/en
Anticipated expiration legal-status Critical
Expired - Fee Related legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
    • C08B—POLYSACCHARIDES; DERIVATIVES THEREOF
    • C08B31/00—Preparation of derivatives of starch
    • C08B31/08—Ethers
    • C08B31/12—Ethers having alkyl or cycloalkyl radicals substituted by heteroatoms, e.g. hydroxyalkyl or carboxyalkyl starch
    • C—CHEMISTRY; METALLURGY
    • C04—CEMENTS; CONCRETE; ARTIFICIAL STONE; CERAMICS; REFRACTORIES
    • C04B—LIME, MAGNESIA; SLAG; CEMENTS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDING MATERIALS; ARTIFICIAL STONE; CERAMICS; REFRACTORIES; TREATMENT OF NATURAL STONE
    • C04B24/00—Use of organic materials as active ingredients for mortars, concrete or artificial stone, e.g. plasticisers
    • C04B24/24—Macromolecular compounds
    • C04B24/38—Polysaccharides or derivatives thereof
    • C04B24/383—Cellulose or derivatives thereof

Definitions

  • Hydroxypropyl starch which is obtained by reacting starch with propylene oxide, is used together with cellulose ethers as a so-called set-up agent in the building industry.
  • the addition of the set-up agent influences the rheology of a plaster and improves its processing properties.
  • the addition of the set-up agent improves the stability of the plaster sprayed on and facilitates processing of the plaster and so-called slurry formation, i.e. the dissolving out and the uniform distribution of minute particles from the plaster applied.
  • the HPS added is highly effective as a set-up agent if thickening occurs after about 10 seconds.
  • the stability of thickening i.e. the high initial viscosity rapidly established must remain intact over a relatively long period of the order of 15 minutes.
  • the present invention provides a process for the production of hydroxypropyl starch having molar substitution degrees (MS) of at most 1, wherein the starch is etherified in the presence of a little water and with an excess of propylene oxide.
  • MS molar substitution degrees
  • HPS produced in accordance with the invention is eminently suitable for use as a set-up agent for gypsum and cement plaster.
  • the process according to the invention had not been expected to lead to a hydroxypropyl starch having a low MS-value, preferably in the range from 0.4 to 0.8, because in the known production of hydroxypropyl cellulose the use of an excess of propylene oxide in the absence of any further inert reaction medium leads to MS-values of from 3 to 5 (U.S. Pat. No. 3,278,520). Because of this, correspondingly higher MS-values had also been expected in the production of HPS by the process according to the invention.
  • Each anhydroglucose unit of the cellulose or starch molecule has three OH-groups.
  • the MS-value indicates the average number of OH-groups substituted per anhydroglucose unit
  • the MS-value is indicative of the average number of moles of the reactant which have been bound per anhydroglucose unit.
  • the MS-value is generally greater than the DS-value.
  • the etherification process according to the invention is generally carried out at 50° to 75° C., preferably at 60° to 70° C., in the presence of from 0.01 to 0.1 mole, preferably from 0.04 to 0.06 mole, of NaOH/mole of starch, a water content of from 10 to 20% by weight, preferably from 15 to 16% by weight, based on propylene oxide and water, and 3 to 10 moles, preferably 4 to 5 moles, of propylene oxide per mole of starch.
  • the reactants After the reactants have been combined, they are either immediately heated to the etherification temperature and etherified for about 4 hours, or alternatively, they are first alkalised for about 1 hour at normal temperature (25° C.), subsequently heated to the etherification temperature and etherified for about 3 hours at that temperature.
  • Neutralisation of the sodium hydroxide used may be carried out with a mineral acid or with an organic acid.
  • the salt content is minimal.
  • the end product does not have to be purified. It is eminently suitable for use as a set-up agent for plasters, particularly gypsum plasters, from 0.005 to 0.08% and preferably from 0.02 to 0.05% of the hydroxypropyl starch produced in accordance with the invention being added to the plaster ingredients.
  • 6.466 g of corn starch (moisture content 9.8%) are introduced into a reactor, followed by the addition of 8,352 g of propylene oxide, consisting of 6,500 g of recovered propylene oxide and 1,852 g of fresh propylene oxide (cf. Example 1), and 226 g of water. 745 g of 9.66% by weight NaOH are sprayed on with uniform stirring, followed by alkalisation for one hour at room temperature. The temperature is then increased to 70° C. and kept at that level for three hours. On completion of etherification, the alkali is neutralised in the same way as in Example 1. Excess propylene oxide is removed and again collected in a cooled receiver. The product has a molar substitution degree of 0.57.
  • a gypsum plaster mix of 70 g of plaster of Paris, 26 g of lime sand, 3.7 g of calcium hydroxide and 0.25 g of methyl cellulose is mixed with 0.05 g of hydroxypropyl starch in a beaker, followed by the addition of 39 g of water and stirring with a wooden spatula.
  • the test is carried out by an expert using for comparison a mix which does not contain any hydroxypropyl starch as set-up agent.
  • the time which it takes the mix to thicken appreciably is measured in seconds.
  • the degree of thickening is qualitatively determined by the resistance to stirring.
  • the stability of thickening is tested by continuing stirring for a prolonged period (at least 15 minutes).
  • the comparison mix containing 0.05 g of the hydroxypropyl starch of Example 3 has such poor thickening effect that the product is unsuitable for use as a set-up agent.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Engineering & Computer Science (AREA)
  • Organic Chemistry (AREA)
  • Ceramic Engineering (AREA)
  • Materials Engineering (AREA)
  • Biochemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Medicinal Chemistry (AREA)
  • Polymers & Plastics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Structural Engineering (AREA)
  • Polysaccharides And Polysaccharide Derivatives (AREA)
  • Curing Cements, Concrete, And Artificial Stone (AREA)

Abstract

A process for the production of hydroxypropyl starch wherein the starch is etherified in the presence of a small amount of water with an excess of propylene oxide which hydroxypropyl starch is used as plaster additive.

Description

Hydroxypropyl starch (HPS), which is obtained by reacting starch with propylene oxide, is used together with cellulose ethers as a so-called set-up agent in the building industry. The addition of the set-up agent influences the rheology of a plaster and improves its processing properties. In particular, the addition of the set-up agent improves the stability of the plaster sprayed on and facilitates processing of the plaster and so-called slurry formation, i.e. the dissolving out and the uniform distribution of minute particles from the plaster applied.
Since the adhesion of the plaster, which is dependent upon the rate of dissolution of the HPS, is intended to increase quickly, the HPS added is highly effective as a set-up agent if thickening occurs after about 10 seconds. In addition to the development of thickening, another important factor is the stability of thickening, i.e. the high initial viscosity rapidly established must remain intact over a relatively long period of the order of 15 minutes.
Processes for the production of HPS are known. They are based on the so-called dry method in which starch is directly reacted with catalytic quantities of a base and the etherifying agent, propylene oxide, (U.S. Pat. Nos. 2,516,632, 2,516,633, 2,516,634 and 2,733,238). The degrees of molar substitution (MS) reached range from 0.05 to 1.5. However, the more advanced method is to carry out etherification in the presence of an inert solvent (U.S. Pat. No. 2,845,417), such as methanol, ethanol, isopropanol or mixtures thereof. Where this procedure is adopted, MS-values of from about 0.4 to 0.9 are reached (U.S. Pat. No. 3,652,539). A disadvantage of this method lies in the fact that the inert reaction medium has to be removed after etherification and the etherifying agent is often difficult to separate therefrom. In addition, the effect of the HPS thus produced may be inadequate.
The present invention provides a process for the production of hydroxypropyl starch having molar substitution degrees (MS) of at most 1, wherein the starch is etherified in the presence of a little water and with an excess of propylene oxide.
The HPS produced in accordance with the invention is eminently suitable for use as a set-up agent for gypsum and cement plaster.
The process according to the invention had not been expected to lead to a hydroxypropyl starch having a low MS-value, preferably in the range from 0.4 to 0.8, because in the known production of hydroxypropyl cellulose the use of an excess of propylene oxide in the absence of any further inert reaction medium leads to MS-values of from 3 to 5 (U.S. Pat. No. 3,278,520). Because of this, correspondingly higher MS-values had also been expected in the production of HPS by the process according to the invention.
The expression "MS-value" is explained in the following:
Each anhydroglucose unit of the cellulose or starch molecule has three OH-groups. Whereas the DS-value indicates the average number of OH-groups substituted per anhydroglucose unit, the MS-value is indicative of the average number of moles of the reactant which have been bound per anhydroglucose unit. For alkyl, caroxyalkyl or acyl derivatives of cellulose or starch, the DS- and MS-values are identical. With hydroxyalkyl derivatives of cellulose and starch, the MS-value is generally greater than the DS-value. The reason for this lies in the fact that, when a hydroxyalkyl group is introduced into the cellulose or starch molecule, an additional OH-group which is also accessible to hydroxyalkylation is formed. It follows from this that side chains of considerable length may be formed in the hydroxyalkylation of cellulose or starch. The MS:DS ration represents the average length of these side chains. It is apparent from this that the DS-value may amount to at most 3 whereas the MS value may assume considerably higher values irrespective of the extent to which the side chains were formed.
The etherification process according to the invention is generally carried out at 50° to 75° C., preferably at 60° to 70° C., in the presence of from 0.01 to 0.1 mole, preferably from 0.04 to 0.06 mole, of NaOH/mole of starch, a water content of from 10 to 20% by weight, preferably from 15 to 16% by weight, based on propylene oxide and water, and 3 to 10 moles, preferably 4 to 5 moles, of propylene oxide per mole of starch. After the reactants have been combined, they are either immediately heated to the etherification temperature and etherified for about 4 hours, or alternatively, they are first alkalised for about 1 hour at normal temperature (25° C.), subsequently heated to the etherification temperature and etherified for about 3 hours at that temperature.
Under the etherification conditions according to the invention, surprisingly only about 10 to 15% of the propylene oxide used in excess is converted into secondary products (mainly propylene glycols) so that around 75% of the propylene oxide used may be recovered and, after topping up with a suitable quantity of fresh propylene oxide, may be used for the next batch.
Neutralisation of the sodium hydroxide used may be carried out with a mineral acid or with an organic acid. By virtue of the small amount of alkali used, the salt content is minimal. For many applications the end product does not have to be purified. It is eminently suitable for use as a set-up agent for plasters, particularly gypsum plasters, from 0.005 to 0.08% and preferably from 0.02 to 0.05% of the hydroxypropyl starch produced in accordance with the invention being added to the plaster ingredients.
EXAMPLE 1
6,466 g of corn starch (moisture content 9.8%) are introduced into a 40-liter-capacity reactor, followed by the addition of 8,352 g of propylene oxide and 226 g of water. 745 g of 9.66% by weight sodium hydroxide solution are then sprayed on with uniform stirring, followed by alkalisation for one hour at room temperature. The temperature is then increased to 70° C. and kept at that level for three hours. A pressure of from 2 to 2.5 bars is established. On completion of etherification, 97.4 g of 85% by weight formic acid are introduced under pressure into the reactor to neutralise the alkali. Excess propylene oxide is then removed and collected in a cooled collecting vessel. 6,500 g of propylene oxide are recovered and, after the addition of 1,852 g of fresh propylene oxide, are used for the next batch. The product has a molar substitution degree (MS) of 0.76.
EXAMPLE 2
6.466 g of corn starch (moisture content 9.8%) are introduced into a reactor, followed by the addition of 8,352 g of propylene oxide, consisting of 6,500 g of recovered propylene oxide and 1,852 g of fresh propylene oxide (cf. Example 1), and 226 g of water. 745 g of 9.66% by weight NaOH are sprayed on with uniform stirring, followed by alkalisation for one hour at room temperature. The temperature is then increased to 70° C. and kept at that level for three hours. On completion of etherification, the alkali is neutralised in the same way as in Example 1. Excess propylene oxide is removed and again collected in a cooled receiver. The product has a molar substitution degree of 0.57.
COMPARISON EXAMPLE 3
3,232.8 g of corn starch (moisture content of 9.8%) 2,320 g of isopropanol and 2,240 g of water are introduced into the reactor. 288 g of 50% by weight NaOH are sprayed on with uniform stirring, followed by alkalisation for one hour at room temperature. On completion of alkalisation, another 15,400 g of isopropanol and 5,200 g of propylene oxide are added. The temperature is then increased to 63° C. and kept at that level for three hours. On completion of etherification, 194.8 g of 85% formic acid are introduced under pressure into the autoclave to neutralise the alkali. The autoclave is then cooled, the reaction product is separated off from the isopropanol and dried at room temperature. The product has an MS-value of 0.43. Test as set-up agent:
A gypsum plaster mix of 70 g of plaster of Paris, 26 g of lime sand, 3.7 g of calcium hydroxide and 0.25 g of methyl cellulose is mixed with 0.05 g of hydroxypropyl starch in a beaker, followed by the addition of 39 g of water and stirring with a wooden spatula.
The test is carried out by an expert using for comparison a mix which does not contain any hydroxypropyl starch as set-up agent. The time which it takes the mix to thicken appreciably is measured in seconds. The degree of thickening is qualitatively determined by the resistance to stirring. The stability of thickening is tested by continuing stirring for a prolonged period (at least 15 minutes).
Gypsum plaster mixes containing additions of 0.05 g of the hydroxypropyl starch of Examples 1 and 2 thicken quickly (in 10 seconds) and show a good thickening effect and very high stability, i.e. the resistance to stirring decreases only slightly over a period of 15 minutes. The comparison mix containing 0.05 g of the hydroxypropyl starch of Example 3 has such poor thickening effect that the product is unsuitable for use as a set-up agent.

Claims (5)

We claim:
1. A process for the production of hydroxypropyl starch having a molar substitution degree of 0.4 to 0.8, said process comprising etherifying starch in the presence of water with an excess of propylene oxide, the water content, based on propylene oxide and water, being 10-20%, by weight, and the amount of propylene oxide present being 3-10 moles per mole of starch.
2. A process as claimed in claim 1, wherein the reaction temperature is from 50° to 75° C.
3. A process as claimed in claim 1, wherein the reaction is carried out in the presence of from 0.01 to 0.1 mole of NaOH per mole of starch.
4. A process as claimed in claim 1, wherein the water content is from 15 to 16% by weight and the amount of propylene oxide present is 4 to 5 moles.
5. A process as claimed in claim 1, wherein the starch is first alkalised at room temperature and then heated to 50° to 75° C.
US06/428,853 1981-10-20 1982-09-30 Process for the production of hydroxypropyl starch Expired - Fee Related US4451649A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
DE19813141499 DE3141499A1 (en) 1981-10-20 1981-10-20 METHOD FOR PRODUCING HYDROXYPROPYL STARCH
DE3141499 1981-10-20

Publications (1)

Publication Number Publication Date
US4451649A true US4451649A (en) 1984-05-29

Family

ID=6144441

Family Applications (1)

Application Number Title Priority Date Filing Date
US06/428,853 Expired - Fee Related US4451649A (en) 1981-10-20 1982-09-30 Process for the production of hydroxypropyl starch

Country Status (5)

Country Link
US (1) US4451649A (en)
EP (1) EP0077949B1 (en)
JP (1) JPS5879002A (en)
DE (2) DE3141499A1 (en)
FI (1) FI69083C (en)

Cited By (19)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5575840A (en) * 1993-10-29 1996-11-19 National Starch And Chemical Investment Holding Corporation Cement mortar systems using blends of polysaccharides and cold-water-soluble, unmodified starches
US6051700A (en) * 1999-02-11 2000-04-18 Grain Processing Corporation Process and method for hydroxyalkylation of starch and hydroxyalkyl starch prepared accordingly
WO2006037774A1 (en) * 2004-10-05 2006-04-13 Voith Patent Gmbh Method for producing a fibrous material web
US20070048490A1 (en) * 2005-06-09 2007-03-01 United States Gypsum Company Low dust gypsum wallboard
KR100764033B1 (en) 2004-12-28 2007-10-09 주식회사 삼양제넥스 Method for preparing hydroxypropyl carboxymethyl starch using dry process
US20080090068A1 (en) * 2005-06-09 2008-04-17 United States Gypsum Company Microstructure features of gypsum wallboard made with high starch and high dispersant level
CN101935356A (en) * 2010-08-17 2011-01-05 邸勇 Method for preparing hydroxypropyl starch ether
US20110195241A1 (en) * 2005-06-09 2011-08-11 United States Gypsum Company Low Weight and Density Fire-Resistant Gypsum Panel
US8197952B2 (en) 2005-06-09 2012-06-12 United States Gypsum Company High starch light weight gypsum wallboard
WO2012091298A1 (en) * 2010-12-29 2012-07-05 Samyang Genex Corporation Method for preparing hydroxyalkyl starch
USRE44070E1 (en) 2005-06-09 2013-03-12 United States Gypsum Company Composite light weight gypsum wallboard
CN103509127A (en) * 2012-06-30 2014-01-15 山东光大科技发展有限公司 Slurry method production process of low-bath-ratio high-substituted hydroxypropyl starch ether
CN105481990A (en) * 2016-01-06 2016-04-13 中州大学 Method for preparing hydroxypropyl starch through green high-pressure method
US20170072069A1 (en) * 2014-02-27 2017-03-16 B-Organic Films Corp. Bioactive agents under water dispersible solid forms for food, nutraceutical, agricultural and pharmaceutical applications
WO2020123934A2 (en) 2018-12-14 2020-06-18 Sappi North America, Inc. Paper coating composition with highly modified starches
US11091565B2 (en) * 2019-10-28 2021-08-17 Shandong Eton New Material Co., Ltd. Preparation method of modified starch ether for improving anti-sliding property of ceramic tile adhesive
US11306028B2 (en) 2005-06-09 2022-04-19 United States Gypsum Company Light weight gypsum board
US11338548B2 (en) 2005-06-09 2022-05-24 United States Gypsum Company Light weight gypsum board
CN115698093A (en) * 2020-03-24 2023-02-03 阿米诺瓦聚合物有限公司 Biocompatible carrier formulations based on modified starches for plant protection and plant growth stimulation or cosmetics and personal care

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE3302988A1 (en) * 1983-01-29 1984-08-02 Henkel KGaA, 4000 Düsseldorf PLASTER MIXTURES WITH A STRENGTH KEETHER CONTENT
JPS6172663A (en) * 1984-09-13 1986-04-14 信越化学工業株式会社 Drip resistant cement mortar composition
SE462100B (en) * 1985-08-08 1990-05-07 Perstorp Ab COMPOSITION AND ITS USE IN A TWO OR MULTIPLE SYSTEM
CN101024706B (en) * 2006-02-22 2010-10-13 西北师范大学 Preparing method of composite catalytic solid-phase prepared hydroxypropyl starch
CN102532330B (en) * 2010-12-21 2014-02-05 北大方正集团有限公司 Method for preparing medium molecular weight hydroxyethyl starch
GB201413832D0 (en) * 2014-08-05 2014-09-17 Tate & Lyle Ingredients Starch compositions useful for thickening aqueous liquids

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2516632A (en) * 1946-08-07 1950-07-25 Penick & Ford Ltd Inc Starch ethers in original granule form
US2516634A (en) * 1947-08-13 1950-07-25 Penick & Ford Ltd Inc Cold-water swelling starch ethers in original granule form
US2516633A (en) * 1947-04-10 1950-07-25 Penick & Ford Ltd Inc Preparation of starch ethers in original granule form
US2733238A (en) * 1951-02-23 1956-01-31 Reaction of starch and alkylene oxides
US2845417A (en) * 1955-10-06 1958-07-29 Penick & Ford Ltd Inc Hydroxyalkylation of ungelatinized starches and dextrins in aqueous, water-miscible alcohols
US3033853A (en) * 1959-04-15 1962-05-08 Hercules Powder Co Ltd Preparation of hydroxyalkyl starches
US3278520A (en) * 1963-02-08 1966-10-11 Hercules Inc Hydroxypropyl cellulose and process
US3378546A (en) * 1965-03-03 1968-04-16 American Maize Prod Co Hydroxypropyl starch ether
US3577407A (en) * 1969-05-19 1971-05-04 Penick & Ford Ltd Highly hydroxypropylated granule potato starch
US3652539A (en) * 1970-03-09 1972-03-28 Nippon Soda Co Process for the production of hydroxypropyl cellulose
US3705891A (en) * 1970-11-04 1972-12-12 Staley Mfg Co A E Method for producing ungelatinized starch derivatives

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2900268A (en) * 1956-11-15 1959-08-18 John C Rankin Process for preparing hydroxyalkylated cereal flour
GB2029431B (en) * 1978-06-23 1983-02-02 Nat Starch Chem Corp Method of preparing hydroxypropylated starch derivatives

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2516632A (en) * 1946-08-07 1950-07-25 Penick & Ford Ltd Inc Starch ethers in original granule form
US2516633A (en) * 1947-04-10 1950-07-25 Penick & Ford Ltd Inc Preparation of starch ethers in original granule form
US2516634A (en) * 1947-08-13 1950-07-25 Penick & Ford Ltd Inc Cold-water swelling starch ethers in original granule form
US2733238A (en) * 1951-02-23 1956-01-31 Reaction of starch and alkylene oxides
US2845417A (en) * 1955-10-06 1958-07-29 Penick & Ford Ltd Inc Hydroxyalkylation of ungelatinized starches and dextrins in aqueous, water-miscible alcohols
US3033853A (en) * 1959-04-15 1962-05-08 Hercules Powder Co Ltd Preparation of hydroxyalkyl starches
US3278520A (en) * 1963-02-08 1966-10-11 Hercules Inc Hydroxypropyl cellulose and process
US3378546A (en) * 1965-03-03 1968-04-16 American Maize Prod Co Hydroxypropyl starch ether
US3577407A (en) * 1969-05-19 1971-05-04 Penick & Ford Ltd Highly hydroxypropylated granule potato starch
US3652539A (en) * 1970-03-09 1972-03-28 Nippon Soda Co Process for the production of hydroxypropyl cellulose
US3705891A (en) * 1970-11-04 1972-12-12 Staley Mfg Co A E Method for producing ungelatinized starch derivatives

Cited By (29)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US5575840A (en) * 1993-10-29 1996-11-19 National Starch And Chemical Investment Holding Corporation Cement mortar systems using blends of polysaccharides and cold-water-soluble, unmodified starches
US6051700A (en) * 1999-02-11 2000-04-18 Grain Processing Corporation Process and method for hydroxyalkylation of starch and hydroxyalkyl starch prepared accordingly
WO2006037774A1 (en) * 2004-10-05 2006-04-13 Voith Patent Gmbh Method for producing a fibrous material web
KR100764033B1 (en) 2004-12-28 2007-10-09 주식회사 삼양제넥스 Method for preparing hydroxypropyl carboxymethyl starch using dry process
US8257489B2 (en) 2005-06-09 2012-09-04 United States Gypsum Company Slurries and methods of making light weight gypsum board
USRE44070E1 (en) 2005-06-09 2013-03-12 United States Gypsum Company Composite light weight gypsum wallboard
US9840066B2 (en) 2005-06-09 2017-12-12 United States Gypsum Company Light weight gypsum board
US20110195241A1 (en) * 2005-06-09 2011-08-11 United States Gypsum Company Low Weight and Density Fire-Resistant Gypsum Panel
US8197952B2 (en) 2005-06-09 2012-06-12 United States Gypsum Company High starch light weight gypsum wallboard
US20080090068A1 (en) * 2005-06-09 2008-04-17 United States Gypsum Company Microstructure features of gypsum wallboard made with high starch and high dispersant level
US11306028B2 (en) 2005-06-09 2022-04-19 United States Gypsum Company Light weight gypsum board
US10406779B2 (en) 2005-06-09 2019-09-10 United States Gypsum Company Light weight gypsum board
US8470461B2 (en) 2005-06-09 2013-06-25 United States Gypsum Company Light weight gypsum board
US10407345B2 (en) 2005-06-09 2019-09-10 United States Gypsum Company Light weight gypsum board
US20070048490A1 (en) * 2005-06-09 2007-03-01 United States Gypsum Company Low dust gypsum wallboard
US11884040B2 (en) 2005-06-09 2024-01-30 United States Gypsum Company Light weight gypsum board
US11338548B2 (en) 2005-06-09 2022-05-24 United States Gypsum Company Light weight gypsum board
US9802866B2 (en) 2005-06-09 2017-10-31 United States Gypsum Company Light weight gypsum board
CN101935356A (en) * 2010-08-17 2011-01-05 邸勇 Method for preparing hydroxypropyl starch ether
WO2012091298A1 (en) * 2010-12-29 2012-07-05 Samyang Genex Corporation Method for preparing hydroxyalkyl starch
CN103270051A (en) * 2010-12-29 2013-08-28 株式会社三养吉尼克斯 Method for preparing hydroxyalkyl starch
CN103509127A (en) * 2012-06-30 2014-01-15 山东光大科技发展有限公司 Slurry method production process of low-bath-ratio high-substituted hydroxypropyl starch ether
US20170072069A1 (en) * 2014-02-27 2017-03-16 B-Organic Films Corp. Bioactive agents under water dispersible solid forms for food, nutraceutical, agricultural and pharmaceutical applications
US12109217B2 (en) * 2014-02-27 2024-10-08 B-Organic Films Corp. Bioactive agents included in functionalized starch having a single helix V-structure
CN105481990A (en) * 2016-01-06 2016-04-13 中州大学 Method for preparing hydroxypropyl starch through green high-pressure method
US10837142B2 (en) 2018-12-14 2020-11-17 Sappi North America, Inc. Paper coating composition with highly modified starches
WO2020123934A2 (en) 2018-12-14 2020-06-18 Sappi North America, Inc. Paper coating composition with highly modified starches
US11091565B2 (en) * 2019-10-28 2021-08-17 Shandong Eton New Material Co., Ltd. Preparation method of modified starch ether for improving anti-sliding property of ceramic tile adhesive
CN115698093A (en) * 2020-03-24 2023-02-03 阿米诺瓦聚合物有限公司 Biocompatible carrier formulations based on modified starches for plant protection and plant growth stimulation or cosmetics and personal care

Also Published As

Publication number Publication date
FI823556L (en) 1983-04-21
FI823556A0 (en) 1982-10-18
FI69083B (en) 1985-08-30
DE3273367D1 (en) 1986-10-23
EP0077949A1 (en) 1983-05-04
DE3141499A1 (en) 1983-04-28
JPS5879002A (en) 1983-05-12
FI69083C (en) 1985-12-10
EP0077949B1 (en) 1986-09-17

Similar Documents

Publication Publication Date Title
US4451649A (en) Process for the production of hydroxypropyl starch
EP2552968B1 (en) New high viscosity carboxymethyl cellulose and method of preparation
US5372642A (en) Use of carboxymethylated methyl hydroxyethyl cellulose ethers or methyl hydroxypropyl cellulose ethers
US2599620A (en) Carboxymethyl ethers
JPH05301901A (en) Water-soluble sulfoalkyl hydroxyl alkyl derivative of cellulose and its use in gypsum-and cement-containing compounds
US5395930A (en) Alkyl hydroxyalkyl cellulose ethers containing sulfoalkyl substituents
UA73294C2 (en) A method for producing low-viscuous water-soluble cellulose ether
US4456751A (en) Multiple stage process for preparing mixed hydroxyalkylcellulose ethers
JPS6354721B2 (en)
JP4950434B2 (en) Method for producing methyl hydroxyalkyl cellulose
US3936313A (en) Method of preparing additives for calcium sulphate plaster
US20080242852A1 (en) Method for Preparation of Hydroxyalkylalkylcellulose Ethers with High Yield
US5591844A (en) Alkyl hydroxyalkyl cellulose ethers containing sulfoalkyl groups
JP2008507602A (en) Process for producing amino acid-containing cellulose derivatives and cosmetic formulations, water treatment and their use in papermaking
EP0235513B1 (en) Alkaline plaster-mix with guar derivatives
JPS58113201A (en) Manufacture of hydroxyalkylcellulose, mixed hydroxyalkylcellulose ether and petroleum collection
MXPA02010035A (en) Method for the production of easily wetted, water soluble, powdered at least alkylated non ionic cellulose ethers.
JPS60192702A (en) Preparation of hydroxyalkylalkylcellulose
CA1236453A (en) Organo-soluble c.sub.3-c.sub.4 hydroxyalkyl ethyl cellulose ethers
JPH09227601A (en) Production of sulfonated cellulose derivative
JPH0469161B2 (en)
JPH0616701A (en) Production of cellulose ether using cyclic ether as precipitation preventive
JPS6256881B2 (en)
CN117440974A (en) Method for producing methylcellulose or hydroxyalkyl methylcellulose
JPH03146502A (en) Production of carboxymethyl ether salt of sweet potato starch pulp

Legal Events

Date Code Title Description
AS Assignment

Owner name: WOLFF WALSRODE, AKTIENGESELLSCHAFT, WALSRODE, GERM

Free format text: ASSIGNMENT OF ASSIGNORS INTEREST.;ASSIGNORS:TEUBNER, HELWIG;OPPERMANN, WILHELM;REEL/FRAME:004052/0480

Effective date: 19820922

FPAY Fee payment

Year of fee payment: 4

REMI Maintenance fee reminder mailed
REMI Maintenance fee reminder mailed
LAPS Lapse for failure to pay maintenance fees
FP Lapsed due to failure to pay maintenance fee

Effective date: 19920531

STCH Information on status: patent discontinuation

Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362

点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载